Here "he" means any person in general. Alternate translation: "Those who love ... are not worthy" or "If you love ... you are not worthy" (See: [[rc://en/ta/man/translate/figs-gendernotations]])
Jesus uses a proverb to teach his disciples. This should be translated with as few words as possible. Alternate translation: "Those who find their lives will lose them. But those who lose their lives ... will find them" or "If you find your life you will lose it. But if you lose your life ... you will find it" (See: [[rc://en/ta/man/translate/writing-proverbs]])